1. The problem statement, all variables and given/known data 1,1,-1,3,-15,105,-945 ... find an expression for the nth term 3. The attempt at a solution I HAVE TO FIND THE PATTERN Now, i know for a fact that there has to be a factorial in there somewhere, because n starts at 0, and as you can see every term is alternating except for the first 2, which means there has to be some kind of factorial in the formula. This is in fact a secondary question. I am trying to find a formula for the nth derivative of sqrt(x+1) and knowing the formula for this sequence is crucial to finding the formula for the nth derivative. So far i have: there must be some factorial in there its not an arithmetic sequence its not a geometric sequence. PLEASE HELP ME!!!